During my trip to Moab I had several people ask what I used on my cladding since it collected almost no dirt/dust. I could not remember the exact name.
The product is Meguiars Natural Shine Vinyl and Rubber Protectant. It comes in a transparant red bottle. For best results use a lint free rag that is dampened with water and apply the Natural Shine to the rag...then rub into the cladding. I use it very infrequently. It lasts a long time. My cladding was still looking half way descent in Moab and I think the last time I used the stuff was at least 18 months ago!